It is often desirable to be able to fasten a cylindrical member within a cylindrical aperture of a piece of equipment to be retained thereto. One common way of retaining the parts together involves the use of an externally threaded clip which is mounted on the end of the cylinder and a internally threaded nut which cooperates with the clip to bear against the surface of the part being retained after threading on the clip member. Difficulties have been encountered with such apparatus by virtue of the fact that the clip member tends to rotate on the cylinder as the nut is being threaded thereon preventing the nut from moving against the part being retained. In U.S. Pat. No. 3,262,673, issued to S. B. Seeley on July 26, 1966, one solution to this problem is presented in the form of a stopper having a threaded bore and a stopper rod having threaded sleeve sections mounted on the rod and adapted to be screwed into the bore. The rod is shown having a reduced section adjacent its lower end part way around the circumference of the rod so as to form an annular abutment shoulder. In order to secure the rod to the stopper, a pair of split sleeve sections are mounted to fit within the reduced portion on the rod and to encircle the rod. When the rod and stopper are assembled, the annular abutment prevents rotation of the sleeve sections. The Seeley invention presents several difficulties since the reduced portions of the rod have to be machined in a time consuming and costly manner and the possibility exists of assembling the split sleeves upside down or leaving one of the sleeve portions out during assembly.